Fire and Fury, Michael Wolff's gossipy tell-all about the inner workings of the Trump administration, has created a media firestorm. Predictably, President Trump's reaction to the book and the attention it received has demonstrated its apparent central theme: that Trump is temperamentally and intellectually unfit for the immensely powerful office he holds. But the book can also help to explain the paradox at the heart of contemporary politics: The more evidence of Trump's unfitness accumulates, the more powerful Republicans are circling the wagons in his defense.

Trump's reaction to Fire and Fury provides a perfect illustration of his character, showing his authoritarian instincts, impulsiveness, disloyalty, and narcissism. He threatened to sue to stop publication of the book, the most dangerous (and flagrantly unconstitutional) form of government censorship. He asserted that when former top strategist Stephen Bannon "was fired, he lost his mind." In an instantly legendary and self-refuting series of tweets, he claimed that "my two greatest assets have been mental stability and being, like, really smart" and that he was "a very stable genius." And at an odd Saturday press conference, he reiterated his wish that the United States had libel laws that prevented books critical of him from being published, repeated his ridiculous argument that Mexico would pay for a wall along the American border, and dismissed claims that his campaign colluded with Russia by quipping: "I do things proper."

Given that Trump's self-evident unfitness for office also comes with an unprecedented level of corruption, you might think that Congress would be using its oversight powers to check him. But the opposite is happening. Not only are Republican legislators refusing to investigate or meaningfully constrain Trump, they're turning the legal apparatus of the state against perceived enemies like Christopher Steele (author of the infamous intelligence dossier about Trump) and, of course, Hillary Clinton.

The reason for this can be found in a remark in Wolff's book attributed to Senate Majority Leader Mitch McConnell: "[Trump] will sign anything we put in front of him." McConnell and Speaker of the House Paul Ryan are often called cowards for refusing to check Trump, but this is exactly wrong. They, and the other members of the House and Senate Republican conferences, are not refusing to check Trump because they're scared of him. They're refusing to check Trump because he's useful to their policy goals. Supporting Trump has given them a 49-year-old ultra-conservative Supreme Court justice and a huge upper-class tax cut that will take health care away from millions of people. These are not very attractive principles to be selling out your country on, but they are principles. And Ryan and McConnell understood the implications of Trump's victory clearly while a lot of pundits were still erroneously assuming there would by a major ideological rift within the Republican Party.

Trump governing as a completely orthodox Republican also explains why he has found it easy to cut Bannon loose. Many people misunderstood Bannon's primary importance as ideological, and assumed Trump would advance a more economically populist agenda than the typical Republican. This was always a misguided assumption. There was never any reason to think Trump, a compulsive liar with no policy knowledge, had any commitment to a populist economic agenda. And even if he did, Ryan and McConnell would be setting the policy agenda, an agenda that would be ruthlessly devoted to advancing the interests of corporations and rich people. Trump has governed consistently with the white nationalist elements of Bannon's thought, but Trump has advanced similar views for far longer than he's known Bannon.

Bannon was important to Trump, but not as some kind of ideological Svengali. As detailed in Joshua Green's important book, Devil's Bargain, his crucial contribution was as a campaign strategist. Through institutions like the Government Accountability Institute, Bannon was able to get negative stories about Hillary Clinton generated by Republican operatives taken seriously by the mainstream media, something he correctly saw as crucial to their success. While the GAI's stories about the Clinton Foundation turned out to be entirely bereft of substance, they helped permanently tar Clinton and paved Trump's way into the White House.

So Bannon played a major role, but with Hillary Clinton in Chappaqua rather than the Oval Office, his usefulness to Trump declined greatly. Trump's policy agenda has been and will continue to be Ryan and McConnell's, which is the only way he can get the legislative "wins" he desperately desires.

And because Trump will advance their agenda, Ryan and McConnell will look the other way, no matter what legal and media investigations reveal about the president. The only way Congress will act to constrain Trump is if Democrats take over one or both houses in 2018.